Cottonwood vs Four O'Clock Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Cottonwood

Cottonwood

Populus deltoides

VS
Four O'Clock

Four O'Clock

Mirabilis jalapa

Cottonwood

Cottonwood

Populus deltoides

The Eastern Cottonwood (Populus deltoides) is a large, fast-growing deciduous tree typically found near rivers and streams. It's known for its broad, triangular leaves that flutter in the wind and its cotton-like seed dispersal in late spring/early summer. Reaching heights of 70-100 feet (or more) with a wide-spreading crown, it's primarily an outdoor tree. People value it for its rapid growth, shade provision, and ecological role in riparian habitats. It is not suitable as an indoor plant due to its size and light requirements.

Salicaceae Eastern and Central North America
✨ Features: Rapid growth, significant shade provision, important riparian habitat tree.
📖 Read Complete Cottonwood Guide
Four O'Clock

Four O'Clock

Mirabilis jalapa

Mirabilis jalapa, commonly known as the Four O'Clock flower, is a bushy, herbaceous perennial typically grown as an annual in cooler climates. It's known for its trumpet-shaped flowers that open in the late afternoon or early evening, releasing a sweet fragrance. The flowers come in a variety of colors, including pink, red, yellow, white, and multicolored variations. It grows from tuberous roots and can reach a height of 1-3 feet. It is primarily grown outdoors in gardens and borders for its vibrant colors and evening fragrance. It is not ideally suited as an indoor plant.

Nyctaginaceae Tropical South America
✨ Features: Flowers open in the late afternoon or early evening and emit a sweet fragrance; flowers come in a variety of colors and can even be multicolored on the same plant.
📖 Read Complete Four O'Clock Guide

Quick Plant Comparison

Feature Cottonwood Four O'Clock
Light Full sun (at least 6 hours of direct sunlight per day) Full sun to partial shade
Watering Weekly for young trees, infrequent deep watering for established trees during dry periods. Every 3-7 days depending on weather and soil drainage
Humidity 20-60% 40-60%
Temperature 10-30°C 18-27°C
Care Level Expert Expert
Growth Rate Fast Fast
Max Height N/A (outdoor tree) 0.3-1 meter (indoors unlikely to reach this height)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-drained soil; tolerates a wide range of soil types, including sandy, loamy, and clay soils. Well-draining soil, such as a mix of garden soil, sand, and compost
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes monthly (monitoring, occasional pruning) 15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Cottonwood

Scientific Name Populus deltoides
Family Salicaceae
Native To Eastern and Central North America
Also Known As Eastern Cottonwood, Plains Cottonwood, Alamo
Leaves The leaves are triangular or deltoid-shaped, 3-7 inches long and wide, with coarsely toothed edges. They are a bright green color in the spring and summer, turning yellow in the fall. The petioles (leaf stalks) are flattened, which causes the leaves to flutter even in a light breeze.
Flowers Cottonwood trees are dioecious, meaning they have separate male and female trees. The flowers are catkins that appear in early spring before the leaves emerge. They are not showy and are primarily wind-pollinated. Flowering does not occur indoors.

Four O'Clock

Scientific Name Mirabilis jalapa
Family Nyctaginaceae
Native To Tropical South America
Also Known As Four O'Clock Flower, Marvel of Peru, Beauty-of-the-Night
Leaves The leaves are ovate to lance-shaped, typically 2-4 inches long, and have a smooth texture. They are usually medium green in color and arranged oppositely along the stems.
Flowers Flowers are trumpet-shaped, about 1-2 inches long, and come in a variety of colors including pink, red, yellow, white, and multicolored. They open in the late afternoon or early evening and emit a sweet fragrance. Flowering indoors is rare and unlikely.

📏 Size & Growth — Plant Comparison

Cottonwood

Height N/A (outdoor tree)
Spread N/A (outdoor tree)
Growth Rate Fast
Growth Pattern The cottonwood grows upright with a single trunk and a broad, spreading crown. It can reach impressive heights and widths, making it a dominant tree in its environment.

Four O'Clock

Height 0.3-1 meter (indoors unlikely to reach this height)
Spread 0.3-0.6 meters (can spread via tuberous roots)
Growth Rate Fast
Growth Pattern Bushy and upright, typically reaching 1-3 feet in height and spread. It grows from tuberous roots, which allow it to regrow each year in warmer climates.

🌱 Propagation — Comparing Plant Growth

Cottonwood

Methods: Stem cuttings, Seed

Difficulty: Easy

Tips: Take hardwood cuttings in late winter or early spring. Root in moist soil or water.

Four O'Clock

Methods: Seed, Tuber division

Difficulty: Easy

Tips: Sow seeds directly in the garden after the last frost or start them indoors 6-8 weeks before. Divide tubers in early spring.

✨ Benefits & Features — Comparing Plant Value

Cottonwood

The cottonwood is known for its rapid growth and the cottony substance attached to its seeds, which aids in wind dispersal. Its leaves have a distinctive triangular shape and flutter easily in the wind.

  • ✓ Provides significant shade in a short amount of time.
  • ✓ Helps stabilize soil and prevent erosion.
  • ✓ Offers habitat and food for wildlife.
  • ✓ Adds natural beauty to the landscape.
  • ✓ Relatively easy to propagate.
  • ⚠️ Toxic to pets

Four O'Clock

The flowers open in the late afternoon or early evening, hence the name 'Four O'Clock'. They are known for their sweet fragrance and the ability to produce multiple colors on the same plant, sometimes even on the same flower.

  • ✓ Adds vibrant color to the garden
  • ✓ Provides a sweet evening fragrance
  • ✓ Attracts pollinators
  • ✓ Relatively low-maintenance once established
  • ✓ Can self-seed and naturalize in suitable climates
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Cottonwood

Repotting N/A (outdoor tree)
Pruning Prune in late winter or early spring to remove dead, damaged, or crossing branches. Regular pruning helps maintain shape and prevent structural issues.
Fertilizing Young trees benefit from a balanced fertilizer (e.g., 10-10-10) in the spring. Mature trees generally don't require fertilization unless soil is deficient.
Seasonal Care Spring: Fertilize young trees. Summer: Monitor for pests and diseases, water during dry periods. Fall: Rake leaves. Winter: Prune dormant branches.

Four O'Clock

Repotting Not typically grown indoors. If grown in containers, repot annually in the spring, especially if root-bound.
Pruning Deadhead spent flowers to encourage more blooms. Prune back stems in late fall to prepare for winter dormancy.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 4-6 weeks during the growing season
Seasonal Care In colder climates, treat as an annual or dig up tubers in the fall and store them in a cool, dry place for replanting in the spring. Reduce watering in the winter.

🌞 Light Requirements

Cottonwood

Full sun (at least 6 hours of direct sunlight per day)

Low light tolerant: ❌ No

Four O'Clock

Full sun to partial shade

Low light tolerant: ❌ No

💧 Watering Needs

Cottonwood

Young trees need regular watering to establish. Mature trees are relatively drought-tolerant but benefit from deep watering during extended dry periods. Overwatering can lead to root rot, especially in poorly drained soils. Signs of underwatering include wilting and leaf drop; overwatering presents as yellowing leaves and potential fungal growth.

Four O'Clock

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. During hot summer months, more frequent watering may be necessary. Reduce watering in cooler months.

🌡️ Temperature & Humidity

Cottonwood

Temperature: 10-30°C

Humidity: 20-60%

Four O'Clock

Temperature: 18-27°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Cottonwood

Cottonwood

Populus deltoides
Care: Expert Time: 30 minutes monthly (monitoring, occasional pruning) Beginner: No

Landowners with large properties seeking a fast-growing shade tree and willing to manage its potential drawbacks.

✅ Choose This Plant If...

  • You need a fast-growing shade tree for a large property.
  • You want to provide habitat for wildlife in a riparian area.
  • You are looking for a tree that can tolerate a wide range of soil conditions.
  • You need a tree to help stabilize soil along a riverbank.
  • You appreciate the sound of leaves fluttering in the wind.

❌ Skip This Plant If...

  • You have a small yard or garden.
  • You are concerned about aggressive root systems damaging structures.
  • You are allergic to pollen.
  • You dislike the cottony seed dispersal.
  • You prefer low-maintenance plants.
📍 Ideal Location: Large, open outdoor space with full sun and well-drained soil, away from buildings and underground utilities.
🎨 Style: Natural, Wild, Rural
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Cottonwood is toxic to horses. The toxic principle is salicylates. Symptoms include decreased appetite, lethargy, colic.
Four O'Clock

Four O'Clock

Mirabilis jalapa
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners looking for a fragrant, colorful addition to their evening garden.

✅ Choose This Plant If...

  • You want a fragrant evening garden
  • You enjoy vibrant, multicolored flowers
  • You want a plant that attracts pollinators like moths and hummingbirds
  • You are looking for a low-maintenance outdoor plant once established
  • You want a plant that can self-seed and return year after year.

❌ Skip This Plant If...

  • You have pets that may ingest the plant
  • You lack a sunny outdoor space
  • You want a plant that thrives indoors.
📍 Ideal Location: Outdoor garden, sunny border, or patio container
🎨 Style: Cottage, Bohemian, Traditional
🏠 Apartment Friendly: No
⚠️ All parts of the plant, especially the seeds and roots, are toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, and abdominal pain. According to the ASPCA, it contains asparagine.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

☀️

Cottonwood needs full sun (at least 6 hours of direct sunlight per day), while Four O'Clock prefers full sun to partial shade.

💡 Pro Tips For Comparing These Plants

Cottonwood Care Tips

Cottonwood is an outdoor tree that requires full sun and ample space. It is not suitable for indoor cultivation. Challenges include its large size, aggressive root system, and susceptibility to certain pests and diseases. Requires regular monitoring and maintenance.

  • Plant in a location with ample space for growth.
  • Water deeply during establishment and dry periods.
  • Monitor regularly for pests and diseases.
  • Prune annually to maintain shape and remove deadwood.
  • Consider the potential for aggressive root growth when choosing a planting location.
❄️ Winter: Cottonwood trees are deciduous and lose their leaves in the winter. No special winter care is needed, but it's a good time to prune dormant branches.
☀️ Summer: Water young trees regularly during dry periods. Monitor for pests and diseases, and treat as needed. Provide adequate space for air circulation to prevent fungal problems.

Four O'Clock Care Tips

Four O'Clocks are primarily outdoor plants and require full sun to thrive. Growing them indoors is challenging due to their high light requirements and potential for pest infestations. They also spread via tuberous roots, which can quickly outgrow a container. Indoor flowering is unlikely.

  • Plant in well-draining soil to prevent root rot.
  • Provide full sun for best flowering.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Protect from strong winds, which can damage the delicate stems.
  • Monitor for pests like aphids and treat promptly.
❄️ Winter: In colder climates, dig up the tubers and store them in a cool, dry place over the winter. Alternatively, treat as an annual and replant in the spring.
☀️ Summer: Provide consistent moisture during the hot summer months. Deadhead spent flowers to encourage more blooms. Monitor for pests and diseases.

⚠️ Common Problems & Solutions — Plant Care Comparison

Cottonwood

Common Issues: Aphids, Cottonwood Leaf Rust, Canker diseases, Aggressive root system
Solutions: Aphids: Insecticidal soap or neem oil. Cottonwood Leaf Rust: Fungicide application. Canker diseases: Prune affected branches. Aggressive root system: Plant away from structures and underground utilities.

Four O'Clock

Common Issues: Powdery mildew, Aphids, Root rot
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Aphids: Spray with insecticidal soap. Root rot: Ensure well-draining soil and avoid overwatering.

❓ Frequently Asked Questions — Comparing These Plants

Cottonwood

What are the light requirements for Cottonwood?

Cottonwood needs bright, indirect light to thrive indoors. Direct sunlight can scorch its leaves, so avoid placing it in a south-facing window without a sheer curtain to filter the light. An east- or west-facing window is generally ideal. If you notice the leaves becoming pale or leggy, it indicates that the plant is not receiving enough light. Consider supplementing with artificial grow lights, especially during the winter months when natural light is limited. Rotate the plant regularly to ensure even light exposure on all sides.

How do I care for Cottonwood?

Cottonwood thrives in bright, indirect light. Water thoroughly when the top inch of soil is dry, ensuring proper drainage to prevent root rot. Maintain moderate humidity levels, especially during drier months. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Repot every 2-3 years in spring, using a well-draining potting mix. Prune regularly to maintain shape and remove any dead or damaged branches. Monitor for pests such as aphids and spider mites, and treat promptly. Provide stable temperatures between 65-75°F (18-24°C). Avoid sudden changes in environment. A pot size appropriate to the tree’s current size and root system is important.

How do I propagate Cottonwood?

Cottonwood can be propagated through stem cuttings or air layering. For stem cuttings, take a 6-8 inch cutting from a healthy stem in spring. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cutting in a pot filled with well-draining potting mix. Keep the soil consistently moist and provide bright, indirect light. Roots should develop within a few weeks. For air layering, make a small cut on a healthy stem and wrap it with moist sphagnum moss. Cover the moss with plastic wrap and secure it with tape. Keep the moss moist and roots should develop within a few weeks. Once roots are visible, cut the stem below the rooted area and plant in a pot.

Four O'Clock

What are the light requirements for Four O'Clock?

Four O’Clocks thrive in full sun, needing at least 6 hours of direct sunlight daily to produce abundant blooms. A sunny location encourages strong growth and vibrant flower colors. While they can tolerate partial shade, reduced sunlight will result in fewer flowers and leggier growth.

How do I care for Four O'Clock?

Four O’Clocks are relatively easy to care for. Plant them in well-draining soil in a location that receives at least 6 hours of sunlight daily for optimal blooming. Water regularly, especially during dry periods, but avoid overwatering, which can lead to root rot. Fertilize monthly during the growing season with a balanced fertilizer or one formulated for blooming plants to encourage abundant flowering.

How do I propagate Four O'Clock?

Four O’Clocks can be propagated through seeds, tubers, or stem cuttings.

Last updated: April 30, 2026 — Plant care data reviewed and verified by our editorial team.